Conducting unit, and conducting methods

ABSTRACT

The invention relates to a delivering unit for gas, comprising a compressor ( 101 ) in a noise-insulation housing ( 20, 40 ), which comprises an inlet opening ( 27, 66 ) and a blow-out opening ( 24, 69, 70 ). An inlet tube ( 96 ) can pneumatically connect the inlet opening to the inlet of the compressor. An outlet tube ( 96 ) can connect the blow-out opening to the outlet of the compressor. A noise absorber ( 60, 80 ) having an inlet chamber ( 73, 97 ) and an outlet chamber ( 74, 98 ) may be accommodated in the noise-insulation housing. Neoprene may be used as lining for the inner walls of the noise-insulation housing. Sheets ( 131. 133 ) may be provided between the noise-insulation housing and the compressor. An inner heat sink ( 42 ) and an inner blower ( 48, 49 ) can cool the compressor. A heat sink ( 41 ) may form one side ( 40 ) of the noise-insulation housing. An outer blower ( 7 ) can cool the heat sink. Blind tubes can be used both at the inlet and the outlet, so as to suppress tonal sound. Moreover, the invention relates to corresponding delivering methods.

The field of the invention relates to delivering units for therapeuticapparatus for splinting the upper respiratory tract, and to deliveringmethods performed by these therapeutic apparatus. More specifically, theinvention relates to delivering units and delivering methods forTNI-apparatus.

TNI-apparatus are known, for example, from WO 02/062413 A2, in whichthey are referred to as anti-snoring apparatus. Such anti-snoringapparatus effect a splinting of the upper respiratory tract byadministering air into the nose of a user via a conventional or modifiedoxygen cannula. Thus, the pressure in the respiratory tract is increasedby some mbar above the ambient pressure. TNI-apparatus refer toapparatus which are suited for transnasal inspiration.

The CPAP-therapy (continuous positive airway pressure) works similarly,whereby nose or face masks are used to administer the air at a pressureof around 5 mbar and at a maximum pressure of 30 mbar. As the masks arepressed against the face during the night, i.e. over a long period oftime, by exerting a certain pressure, skin irritations may occur and, asa result, problems may arise in the acceptance by the patient.

Moreover, evaporators, specifically respiratory humidifiers, are known.In combination with the present invention, the evaporator known from WO2006/012877 can be used particularly advantageously.

In CPAP-apparatus, frequently radial blowers for delivering air areapplied, which are well suited for the small pressures of below 30 mbar,typically 5 mbar, and high flows of up to 150 l/min. Due to the smallertube diameters and, as a result thereof, the higher pressures of 150mbar at the inlet of the nasal cannula, side channel compressors aresuited better for TNI-apparatus. However, the problem about side channelcompressors is the high noise development both at the inlet and theoutlet. In addition, cooling ribs of the side channel compressor housingmay be caused to vibrate due to the high periodic fluctuations in theinterior of the side channel compressor, thereby emitting noise.Finally, the cooling of the side channel compressor must be consideredwith care, because the efficiency of a side channel compressor istypically lower than that of radial blowers, and also because thegeneration of higher pressures of 150 mbar requires more power while therate is the same.

Although the noise development of radial blowers is very moderate ascompared to side channel compressors, noise-insulation boxes are used inCPAP-apparatus, which lower the noise emission of CPAP-apparatus to therange of 30 dBA. In order to prevent the noise from being conductedthrough the air channels to the outside or into the respiratory tube,bypasses are installed in the noise-insulation box. This works accordingto the principle that an airflow can be diverted, while the noisecannot, which is clearly attenuated with each diversion. The standard istwo to three bypasses, as each bypass increases the pressure losscoefficient.

A blower unit is known from WO 2004/046556 A2, which reduces the noisedevelopment in the blower unit, inter alia, by grids.

It is the object of the invention to provide a delivering unit and adelivering method, which allow for an acceptable noise emission.

This object is achieved with the teaching of the independent claims.

Preferred embodiments of the invention are defined in the dependentclaims.

In a surprisingly advantageous manner, flexible connecting tubes betweena pre noise absorber and a compressor and the post noise absorber andthe pre noise absorber can provide both the conduction of air and themechanical support of the pre noise absorber and the compressor, wherebythe transmission of structure-borne noise is kept small.

Advantageously, a pressure-tight closure of the noise-insulation housingdoes not allow any direct noise to escape to the outside.

Below, a preferred embodiment of the invention will be explained in moredetail by means of the accompanying drawings. In the drawings:

FIG. 1 shows an exploded view of a TNI-apparatus according to theinvention;

FIG. 2 shows an exploded view of a noise box of the TNI-apparatus;

FIG. 3 shows an exploded view of a post noise absorber of theTNI-apparatus;

FIG. 4 shows a top view of the post noise absorber;

FIG. 5 shows an exploded view of a pre noise absorber of theTNI-apparatus;

FIG. 6 shows a perspective view of the pre noise absorber;

FIG. 7 shows an exploded view of a heat sink unit of the TNI-apparatus;and

FIG. 8 shows a top view of the heat sink unit.

FIG. 1 shows an exploded view of a TNI-apparatus 1 according to theinvention. The TNI-apparatus 1 substantially comprises a housing bottom2, a housing hood 3, a noise box housing 20 and an outer heat sink 41.Ambient air is aspirated through a filter cover 5 and an air filter foam4 into a filter shaft 31 in the housing hood 3. Webs 32 are provided onthe bottom of the filter shaft 31, so that the air filter foam 4 doesnot directly sit on the bottom of the filter shaft 31 and air isaspirated over the total width of the air filter foam 4. A nozzle 33 islocated on the bottom of the filter shaft 31, over which the first inlettube 15 is pushed. In FIG. 1, the first inlet tube 15 is shown in amounted condition and has approximately the profile of the number “5”without the upper bar. The excess length of the first inlet tube 15 isadvantageous for the mounting and serves the noise control.

The lower end of the first inlet tube 15 is fitted onto a T-piece 16.From the T-piece 16, a second inlet tube 17 leads to an inlet connectionpiece 19, which leads into the inlet opening 27 of the noise box housing20. A sealing ring made of an elastic material, e.g. silicone, serves toenclose the inlet connection piece 19 in the inlet opening 27. Moreover,an inlet λ/4-tube 18 is connected to the T-piece 16, the end of which issealed with a plug. A tube sealed at one end can be called a blind tube.The side channel compressor 101 generates a tonal sound at about 200 Hz,whereby the center frequency of this sound emission depends on therotational speed of the side channel compressor 101, which, again,depends on the required airflow, so that the center frequency fluctuatesby about 200 Hz. The three tubes 15, 17 and 18 define a notch filter,which suppresses sound frequencies by 200 Hz or at least stronglyattenuates them. The length of the first inlet tube 15 is 320 mm. Thelength of the inlet λ/4-tube 18 is 450 mm and the length of the secondinlet tube 17 is 300 mm.

On the blow-out opening of the noise box housing 20 a short blow-outconnection piece 12 with a sound absorber connection 14 is provided,onto which a blow-out sound absorber 13 is pushed. The blow-out soundabsorber 13 is formed of a blind tube having a length of 500 mm, whichis rolled up between a backside 21 of the noise box housing 20 and thecorresponding wall of the housing hood 3. All tubes have an innerdiameter of 8 mm. Like a notch filter, the blow-out sound absorber 13likewise acts at 200 Hz. As a nasal cannula is connected via ahumidifier to the blow-out connection piece, with the nasal cannulastrongly attenuating the sound, the noise absorption on the blow-outside is much less critical as on the inlet side. However, it wasobserved that the lid of the humidifier known from WO 2006/012877 A1 canbe resonantly excited by tonal sound. This can be most efficientlysuppressed by the blow-out sound absorber 13, which is adjusted to theresonance of the lid of the humidifier.

At the moment it is unclear, how sharp the resonance of the lid of thehumidifier is. Therefore, in another embodiment, also the blow-out soundabsorber may be adjusted to the sound emission of the side channelcompressor 101 of about 200 Hz.

In other embodiments, also more complicated embodiments of resonantinlet sound absorbers can be used, wherein several inlet λ/4-tubesconnect T-pieces, to which λ/4-blind tubes are connected, whereby eachpair of tubes, i.e. the tube extending from a T-piece and the blind tubeconnected to the T-piece, is adjusted to a different sound wavelengthand, thus, sound frequency, that is, for example, 180 Hz, 200 Hz and 220Hz, so as to favorably attenuate the range of 170 Hz to 220 Hz by threenotches. Thus, a good attenuation can also be achieved at differentdelivering rates and at the different compressor speeds resultingtherefrom. Such multi-stage sound absorbers can also be used on theblow-out side.

Furthermore, it has been found that, given the great pressure differencebetween inlet and outlet of 150 mbar (CPAP-apparatus: 100 l/min, about15 mbar), the typical airflow of 10 to 50 l/min in a TNI-apparatus isnot enough to sufficiently cool the TNI-apparatus. Therefore, the outerblowers 7 arrange for an airflow from venting slots 26 in the housingbottom 2 through the outer heat sink 41 past the blower tower 6 throughthe outer blowers 7 through a power supply unit 8 to the venting slots34 in the housing hood 3. For noise-protection reasons, the lower edgeof the blower tower 6 is bent away from the outer heat sink 41 over thetotal width. The bent-away part 30 has a height of approximately 1 cm.

To insulate it against the transmission of structure-borne noise, thenoise box housing 20 stands on rubber-metal buffers 23 in correspondingrecesses in the housing bottom 2.

In addition, the power supply unit 8 is insulated against the noise boxhousing 20 by an insulating foil 9 made of Macrolon. The printed circuitboard 10, too, is insulated against the noise box housing 20 by such aninsulating foil 11. To communicate with the outside world the printedcircuit board 10 is provided with a sub-D-socket, which is accessiblefrom outside through a recess 29 in the housing bottom 2. In the opening25 an apparatus connector 28 is mounted.

To allow a better orientation, the left side 22 of the noise box housing20 is shown, with the outer heat sink 41 forming the front side.

FIG. 2 shows an exploded view of the noise box housing 20. On the frontside, the heat sink unit 40 is removed, which will be explained in moredetail by means of FIGS. 7 and 8. The interior of the noise box housingis substantially formed by the side channel compressor 101, whichgenerates the noise, a pre noise absorber 80, which will be explained inmore detail by means of FIGS. 5 and 6, and a post noise absorber 60,which will be explained in more detail by means of FIGS. 3 and 4.

To permit a further noise absorption, a mass element 131, silicone foambuffers 132 having a thickness of 3 mm, a mass rear wall 133 and anabsorber element 134 as well as an absorber rear wall 135 are provided.The mass element 131 is formed of a steel sheet ST37, which is bent in aU-shaped manner and has a thickness of 1.5 mm and which shields theupper side and the major part of the left and right inner side of thenoise box housing 20. The mass rear wall is likewise made of a steelsheet ST37 having a thickness of 1.5 mm and internally shields thebackside 21. The vibrations of the steel sheets caused by the noise areinternally attenuated by the absorber element 134 and the absorber rearwall 135 and externally by the silicone foam buffers 132. The absorberelement 134 and the absorber rear wall 135 are made of neoprene having athickness of 6 mm. Neoprene is thermally more stable, but lessbio-compatible than noise-insulation foam. The absorber element 134 andthe absorber rear wall 135 absorb the noise before it hits the masselement 131 and the mass rear wall 133. The mass element 131 rests onsupports 64, which are made of 2 mm of silicone foam, on a housing shell61 of the post noise absorber 60. The side parts of the mass element 131do, therefore, not extend to the bottom side of the noise box housing20.

To avoid the transmission of structure-borne noise, the side channelcompressor 101, the pre noise absorber 80 and the post noise absorber 60are not directly connected to each other, but the side channelcompressor 101 is connected to the pre noise absorber 80 by the twotubes 96 and the spacers 95. The post noise absorber 60 is looselyconnected to the pre noise absorber 80 by a tube 71, by another coveredtube and by a spacer 72. Only if the apparatus is turned over to oneside, or in the event of impacts against the apparatus, e.g. duringtransport, it must be ensured by limit stops that the side channelcompressor 101 and the pre noise absorber 80 are not displaced out oftheir specified position. No problems will arise, however, if the sidechannel compressor 101 hits against the absorber element 134 and theabsorber rear wall 135. An impact protection 47, which is illustrated inFIGS. 7 and 8, is provided on the front side.

Also the blocks 85 having a neoprene layer 86 serve as limit stops, forexample, if the TNI-apparatus is put down roughly. Normally, however, anair gap having a width of 1-2 mm is provided between the lower edges ofthe heat sink of the side channel compressor 101 and a neoprene layer 86so as to avoid a transmission of structure-borne noise. Similarly, thisrefers to the impact protection 65 which, like the supports 64, is madeof a silicone foam of 2 mm thickness. Normally, an air gap having awidth of 1-2 mm is also provided between the impact protection 65 andthe lower side of the pre noise absorber 80. Also between the upper sideof the side channel compressor 101 and the absorber element 134 an airgap having a width of 1-2 mm is normally provided.

A seal 63 made of silicone foam having a thickness of 3 mm forms thelower side of the post noise absorber 60. The seal 63 projects over thehousing shell 61. During the assembly, the projecting parts are foldedupwardly to the sides of the housing shell 61, so that the blow-outopenings in the housing shell 61 and in the seal 63, 69 and 70 are inalignment. In the mounted condition, the seal 63 is pressed togetherbetween the lower side of the noise box housing 20 and the housing shell61.

FIG. 3 represents an exploded view of the post noise absorber 60, whichis turned upside down. The housing shell 61 comprises a total of 12screw holes, so that the lower side of the noise box housing 20 ispressed sufficiently uniformly against the housing shell 61 in themounted condition and the seal 63 can fulfil its function. The two inletopenings 27 and 66 in the noise box housing 20 and in the seal 63,respectively, are then in alignment. The seal 63 is made of a siliconefoam having a thickness of 3 mm. Inside the housing shell 61 one can seea total of seven chambers, whereby the three chambers on the left andthe chamber in the middle are referred to as inlet chambers 73 and servethe noise absorption on the inlet side. The three chambers on the rightserve the noise absorption on the blow-out side and are referred to asoutlet chamber 74. That is, the air to be administered flows from theinlet opening 66 through four chambers toward the outlet opening 67,through the pre noise absorber 80 toward the side channel compressor 101and under a positive airway pressure back to the pre noise absorber 80and subsequently from an inlet opening 68 to the blow-out opening 69.

As was mentioned above, there is a pressure difference of approximately150 mbar between the inlet side and the outlet side, so that inparticular the blow-out side has to be sealed with respect to the inletside and also with respect to the ambient pressure. Approximately theupper half (shown at the bottom of FIG. 3) of each chamber is filledover a possibly large area with a blank of noise-absorbing foam 62. Inone portion of the chambers connections for the outlet opening 67 andthe inlet opening 68 are integrated. The blank for the chamber with theblow-out opening 69, too, is devoid of a corner so as not to seal theblow-out openings 69.

FIG. 4 shows a top view of the housing shell 61, including the outletopening 67, the inlet opening 68, the supports 64 and the impactprotection 65.

FIG. 5 shows an exploded view of the pre noise absorber 80, which issubstantially formed by a lower housing shell 81 and an upper housingshell 84. The two housing shells 81 and 84 define an inlet chamber 97and an outlet chamber 98, which are sealed against the ambiance andagainst each other in a pressure-tight manner by a seal 83. In bothchambers in the lower housing shell a blank of noise-absorbing foam 82is provided. The air coming from the post noise absorber 60 passesthrough the inlet 91 into the inlet chamber 97 and flows through theoutlet 92 further to the side channel compressor 101. Coming from theside channel compressor 101, the delivered air flows through the inlet93 into the outlet chamber 98 and leaves the same again through theoutlet 94 in the direction of the post noise absorber 60.

Air conduction seals 87-90 made of noise-absorbing foam as well asblocks 85 having neoprene layers 86 are glued onto the upper housingshell 84. As was mentioned above, the blocks 85 serve as an impactprotection. The air conduction seals 87-90 serve to concentrate theforced convection generated by the heat sink unit 40 to the coolingplates.

FIG. 6 shows a perspective view of the assembled pre noise absorber 80.

FIG. 7 shows an exploded view of the heat sink unit 40. The heat sinkunit is substantially produced from a machined extruded profile, whichforms the outer heat sink 41. The edge 55 of the thick part of the outerheat sink 41, which connects the cooling ribs, is partially milled off,so as to enter with the milled-off portion 56 into the noise box housing20 and to be fixed to the same by screws. On the edge of the milled-offportion 56 on the side of the cooling ribs a sealing groove 51 issinked, into which a seal 52 is inserted so as to connect the outer heatsink 41 to the noise box housing 20 in a pressure-tight manner. On theedge, a recess 53 is additionally sinked, which serves as a cableleadthrough.

On the inner side of the outer heat sink 41 a recess 54 is sinked aswell, into which four inner heat sinks 42 are mounted. However, only oneinner heat sink 42 is illustrated in all relevant FIGS. 2, 7 and 8. Inthe embodiment illustrated, the inner heat sinks 42 are finger heatsinks. An air conduction sheet 50 is screwed onto the inner heat sinks42. On the air conduction sheet 50, again, two inner blowers 48 and 49,air conduction seals 43 to 46 as well as the impact protection 47 areattached. The air conduction seals 43 to 46 serve to make the innerblowers 48 and 49 aspirate air above all through the cooling ribs of theside channel compressor 101. Then, the air flows through the inner heatsinks 42, along the inner side of the absorber element 134 and betweenthe pre noise absorber 80 and the post noise absorber 60 to the absorberrear wall 135, to be aspirated again through the cooling ribs of theside channel compressor 101. The air conduction seals 43 to 46 are madeof noise-absorbing foam, thus helping to attenuate noise inside thenoise box housing 20.

The edgewise affixed noise-absorbing foam pieces 43 to 46 aremechanically not stable enough to hold the side channel compressor 101.This is accomplished by the impact protection 47, which is made of apolycarbonate block with a neoprene layer of a thickness of 2 mm.

FIG. 8 shows a top view of the inner side of the heat sink unit 40.

Although TNI-apparatus are usually used to deliver and administerambient air, other gases can be delivered as well. Also, medicine, e.g.in the form of aerosols, or anesthetic gases may be added to thedelivered gas.

Above, the invention was explained in more detail by means of preferredembodiments. A person skilled in the art will appreciate, however, thatvarious alterations and modifications may be made without departing fromthe spirit of the invention. Therefore, the scope of protection will bedefined by the accompanying claims and their equivalents.

LIST OF REFERENCE NUMBERS

-   1 TNI-apparatus-   2 housing bottom-   3 housing hood-   4 air filter foam-   5 filter cover-   6 blower tower-   7 outer blower-   8 power supply unit-   9 insulating foil-   10 printed circuit board-   11 insulating foil-   12 blow-out connection piece-   13 blow-out sound absorber-   14 sound absorber connection-   15 first inlet tube-   16 T-piece-   17 second inlet tube-   18 inlet λ/4-tube-   19 inlet connection piece-   20 noise box housing-   21 backside-   22 left side-   23 rubber-metal buffer-   24 blow-out connection piece opening-   25 opening-   26 venting slots-   27 inlet opening-   28 apparatus connector-   29 recess-   30 bent-away part-   31 filter shaft-   32 web-   33 nozzle-   34 venting slots-   40 heat sink unit-   41 outer heat sink-   42 inner heat sink-   43-46 air conduction seal-   47 impact protection-   48, 49 inner blower-   50 air conduction sheet-   51 sealing groove-   52 seal-   53, 54 recess-   55 edge-   56 milled-off portion-   60 post noise absorber-   61 housing shell-   62 noise-absorbing foam-   63 seal-   64 supports-   65 impact protection-   66 inlet opening-   67 outlet opening-   68 inlet opening-   69, 70 blow-out opening-   71 tube-   72 spacer-   73 inlet chambers-   74 outlet chambers-   80 pre noise absorber-   81 lower housing shell-   82 noise-absorbing foam-   83 seal-   84 upper housing shell-   85 block-   86 neoprene layer-   87-90 air conduction seal-   91, 93 inlet-   92, 94 outlet-   95 spacer-   96 tube-   97 inlet chamber-   98 outlet chamber-   101 side channel compressor-   131 mass element-   132 silicone foam buffer-   133 mass rear wall-   134 absorber element-   135 absorber rear wall

1. Delivering unit for gas, comprising a compressor having an inlet andan outlet; a noise-insulation housing, in which the compressor isprovided, wherein the noise-insulation housing comprises an inletopening and a blow-out opening; characterized by: an inlet tube, whichpneumatically connects the inlet opening of the noise-insulation housingto the inlet of the compressor; and an outlet tube, which pneumaticallyconnects the blow-out opening of the noise-insulation housing to theoutlet of the compressor.
 2. Delivering unit according to claim 1,characterized in that the inlet tube and the outlet tube mechanicallysupport the compressor in the noise-insulation housing.
 3. Deliveringunit according to claim 1, characterized in that the space outside thecompressor, inside the noise-insulation housing and outside the inlettube and the outlet tube is sealed in a pressure-tight manner. 4.Delivering unit according to claim 1, characterized in that a noiseabsorber is accommodated inside the noise-insulation housing, whichcomprises an inlet chamber and an outlet chamber each with an inlet andan outlet, wherein the inlet opening of the noise-insulation housing ispneumatically connected to the inlet of the inlet chamber, wherein theoutlet of the inlet chamber is pneumatically connected via the inlettube to the inlet of the compressor, wherein the outlet of thecompressor is pneumatically connected via the outlet tube to the inletof the outlet chamber, wherein the outlet of the outlet chamber ispneumatically connected to the blow-out opening of the noise-insulationhousing.
 5. Delivering unit for gas, comprising a compressor having aninlet and an outlet; a noise-insulation housing, in which the compressoris provided, wherein the noise-insulation housing comprises an inletopening and a blow-out opening; characterized by: a noise absorber,which is accommodated inside the noise-insulation housing, whichcomprises an inlet chamber and an outlet chamber each with an inlet andan outlet, wherein the inlet opening of the noise-insulation housing ispneumatically connected to the inlet of the inlet chamber, wherein theoutlet of the inlet chamber is pneumatically connected to the inlet ofthe compressor, wherein the outlet of the compressor is pneumaticallyconnected to the inlet of the outlet chamber, wherein the outlet of theoutlet chamber is pneumatically connected to the blow-out opening of thenoise-insulation housing.
 6. Delivering unit according to claim 4,characterized in that the noise absorber is formed of a housing shelland a wall of the noise-insulation housing, wherein a sheet-shaped sealseals the outlet chamber against the inlet chamber and the interior ofthe noise-insulation housing.
 7. Delivering unit according to claim 5,characterized in that inside the noise-insulation housing between thenoise-absorber and the compressor a pre noise absorber having an inletchamber and an outlet chamber each with an inlet and an outlet isprovided, wherein the outlet of the inlet chamber of the noise absorberis pneumatically connected to the inlet of the inlet chamber of the prenoise absorber, wherein the outlet of the inlet chamber of the pre noiseabsorber is pneumatically connected to the inlet of the compressor,wherein the outlet of the compressor is pneumatically connected to theinlet of the outlet chamber of the pre noise absorber, wherein theoutlet of the outlet chamber of the pre noise absorber is pneumaticallyconnected to the inlet of the outlet chamber of the noise absorber. 8.Delivering unit according to claim 1, characterized in that four innersides of the walls of the noise-insulation housing are partially linedwith neoprene.
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 20. Delivering method forgas, comprising delivering the gas through the compressor from an inletof the compressor to an outlet of the compressor; characterized by:delivering the gas through an inlet tube, from the inlet opening of anoise-insulation housing to an inlet of a compressor; delivering the gasthrough an outlet tube from the outlet of the compressor to a blow-outopening of the noise-insulation housing.
 21. Delivering method accordingto claim 20, further characterized by mechanically supporting thecompressor by the inlet tube and the outlet tube in the noise-insulationhousing.
 22. Delivering method according to claim 20, furthercharacterized by sealing the space outside the compressor, inside thenoise-insulation housing and outside the inlet tube and the outlet tubein a pressure-tight manner.
 23. Delivering method according to claim 20,further characterized by noise absorption by a noise absorber inside thenoise-insulation housing, which comprises an inlet chamber and an outletchamber each with an inlet and an outlet, wherein the inlet opening ofthe noise-insulation housing is pneumatically connected to the inlet ofthe inlet chamber, wherein the outlet of the inlet chamber ispneumatically connected via the inlet tube to the inlet of thecompressor, wherein the outlet of the compressor is pneumaticallyconnected via the outlet tube to the inlet of the outlet chamber,wherein the outlet of the outlet chamber is pneumatically connected tothe blow-out opening of the noise-insulation housing.
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